David Ornstein has revealed that one of the best young players in the world is on the verge of leaving Arsenal this summer. The Gunners have built a fantastic youth setup over the years. Hale End has always been the home to exceptional talents, and Per Mertesacker has taken the academy to a whole new level since he took charge. One Arsenal youngster has made more noise over the last year than anyone else in the club’s academy. Unfortunately for the Gunners, he could be on his way out now. The sad news for Arsenal fans is that he could end up at Manchester United. David Ornstein says Chido Obi-…